Techniques and materials

With the acceptance of Christianity in 988, Old Rus absorbed not
only the theological concept of the icon, but also the technology
of its embodiment in paint. Painting with colours prepared with egg
yolk is one of the most ancient techniques: it was widely employed
in ancient Egypt, for instance, where egg tempera was used to
decorate sarcophagi.

The creation of an icon began with the
preparation of the foundations beneath the painting. Usually the
icon panel was assembled from one or more panels of well-dried
wood, prepared with an axe. According to the rules, they used the
wood of lime trees, rarely pines, and even more rarely spruce
panels. If the older icons of the 12th to 15th centuries were
mostly painted on linden panels regardless of their place of
origin, then in the later 17th to 19th centuries it is not unusual
to find woods such as alder, poplar, juniper and spruce used
[1]. Wood was prepared
in the winter at times of severe frost, when it contained the least
moisture. The tree trunk was split into panels with the help of an
axe and wedges, removing the external, soft layer of wood
(sapwood), and was dried out over a period of several years. This
way of working does not destroy the cellulose fibres which make the
panels more durable and prevent decay. In rare cases panels of
different species are found in a single icon, as for example in the
13th-century royal gates from the Assumption Cathedral in Krivoe
Pogost (Tretiakov Gallery, Moscow), where both lime and pine were
used [2].

In the 12th to 15th centuries, icon panels
were mounted in the Byzantine tradition by battens superimposed on
the reverse side, or on the upper and lower edges of the icon, with
the help of wooden or beaten iron pegs. The battens were fastened
against the grain of the wood fibres, thus preventing in theory any
warping of the panel. Between the horizontal battens, additional
diagonal splints in the shape of the letters Z or X were often
fastened. Battens superimposed on edges were decorated with red
paint, which in later times led to the tradition of decorating the
lower and upper edges with red margins – the so-called ‘opush’.

From the 15th century onwards Russian masters
abandoned the ‘Greek’ mounting of panels, which led to stresses and
cracks in the wood as a result of too rigid fastenings, and began
to introduce wedge-shaped battens into grooves cut into the reverse
of the icon. This tradition continues to this day, and is a
characteristic feature of Russian icons influenced in the 18th and
19th centuries by Greek and Balkan masters. With the appearance of
the new method, superimposed battens were replaced with cut-in ones
on most of the oldest icons.

On the front of Russian icons, a depression
was hollowed out for the main representation – the so called
‘kovcheg’ (ark or shrine), which was separated from the elevated
margin or border by the ‘luzga’, a shallow angled edge. Without
doubt, the designation of this hollowed-out surface for the holy
image by the word ‘kovcheg’ also had a sacred meaning. Like Noah’s
Ark, the icon, with its ark-harboured image, also bore salvation.
Only from the end of the 17th century did flat panels without
depressions begin to be prepared, in the manner of European
paintings on canvas.

The defects of the panel, joins and the
surface for the main depiction were covered with pieces of old,
washed-out linen cloth. This ensured that the base coat adhered
better to the surface of the panel. Painters to this day call the
base coat or primer (gesso) by the old word ‘levkas’, which derives
from the name of the Greek island of Lefkas, from whence came chalk
of the very best quality. Incidentally, the Russian name for the
material ‘ mel’ (calcium carbonate, chalk) – itself comes from the
name of another Greek island – Melos. ‘Levkas’ or gesso for icons
was made from chalk, a mixture of gypsum and chalk, or gypsum
alone. The powder was mixed with animal hide glue according to an
ancient Byzantine recipe. Only from the end of the 17th century
onwards do Russian sources begin to recommend fish glue, made from
the dried bladder of the sturgeon. In antiquity fish glue was
called ‘karluk’ after the tribe which dwelt in the lower Volga
region around the Caspian Sea.

Onto a meticulously, but not excessively,
polished primer ‘levkas’, the drawing was plotted in black paint by
brush or transferred by tracing. The surface of old icons was
always a little uneven, in order to create a play of light. Then
the painter proceeded to gild the halos and backgrounds. Very thin
leaves of gold were laid on the ochre-stained, translucent surface
with the aid of animal glue, garlic juice and, later, the so-called
‘poliment’, prepared according to a Greek recipe.
‘Poliment’ consisted of processed egg white, beeswax, soap
and bole – red Armenian clay. Along with gold they often used
silver, and on a few old icons we even see tin. So as not to lose
the contours of the representations during the gilding process, the
lines of the drawing were scratched out with a needle.